Topic: Clear coat engine instead of paint?

[zeech]

Not sure if anyone has done this before, I searched around and didn't see much. I'm got my engine for my CB750 pretty much all blasted and was wondering if anyone has clear coated the raw aluminum as opposed to painting it? I was going to use the Duplicolor Aluminum color but was wondering if this option was viable as well.

If so, what sort of high temp clear coat exists out there? Thanks as always.

[harisuluv]

I don't know of any high temp clear myself. The duplicolor is good stuff though.

[HondaMan]

Before the K2, many of the old-factory cases were clear-coated. The top ends were usually painted. During the K2, the clear coating stopped and the engines were all painted. I suppose it reduced the expense of matching and polishing the cases, and by then the bike was such a big hit that no one really seemed to care that much how they looked.

[Jlovvorn]

Does painting have any effect on cooling?

When I was doing my 305 I was wondering if painting was just encasing the engine, and thus reducing cooling.  A layer of paint is an insulator.

Probably a crap theory, but I am curious.

[calj737]

Painting the cylinders "will" affect the cooling. How much, what I'll effect? That's very arguable. Possibly not enough to notice (looks like you live in WDC) unless you sit in Beltway traffic endlessly. Paint away! Or clear coat the cases, upper end and leave the jugs raw.

I think you'd be fine in your climate.

[Jlovvorn]

Thanks!  Good to know.

[zeech]

Is there any issue with leaving the entire thing unpainted and simply blasted? It's pretty porous and seems like it would swallow of grease and grime and get real nasty...?

[Rookster]

The Hi Temp Duplicolor clear will turn a brownish/purple color from the heat.  The can says 500 degrees but the engine heat will discolor it.  British engines were left raw aluminum.  The CB750 engine will start to corrode over time though.  You will get the white powder like residue in between the fins that will be hard to clean.  I would just paint it with the Duplicolor Hi Temp Aluminum paint.  It is very good stuff.

Scott

[Frostyboy]

I'm still not sure of when I'm going to do it, but when I pull my engine down I think I'll be going down the path of wetblasting. I saw this guy's work at his stand at this years Laverda Concours. He had engine parts that were done ages & ages ago & no sign of deterioration or oxidization. Just clean & shiny. Not shiny like polished, but really clean looking.
Here's his site with some great examples of his work.
http://www.wetblasting.net/
Make sure to go to the gallery as well, there's a 750 in there among others.

[PeWe]

I have clear coated blasted aluminum. To summer 1984. Bike used until 1990, then in 2 different cold barns
Not the engine...